What does error code E109 mean on a Navien tankless water heater?

Fan motor fault. Abnormal operation of the fan motor.

Can I fix Navien code E109 myself?

Start with these safe checks: Clean the intake air filter. If it continues, contact Navien technical support.

When should I call a technician for code E109?

If it continues, contact Navien technical support. Smell gas? Leave right away, don't touch light switches or phones inside, and call your gas utility or 911 from outside. Never open a gas valve, burner, gas line, vent or flue connection, or bypass a safety switch. Repeated lockouts, scorching, soot, or a CO alarm mean shut it off and call a licensed gas technician.

Navien tankless water heater error code

Navien tankless water heater code E109: Fan motor fault

Navien NPE-2 tankless water heaters

What E109 means

Abnormal operation of the fan motor.

Likely causes

Dirty intake air filter

Safe first checks

Clean the intake air filter.

When to stop

If it continues, contact Navien technical support.

Checked against: Navien NPE-2 user's information manual: understanding error codes. Codes can differ by model and year, so confirm with your owner's manual.